Installing windows/games on external HDD?

[Fugue]

I recently purchased a Seagate Backup Plus 1TB hard drive (USB 3.0) and I have a few questions.

I'm using a 2012 MBA and I want to install some games on the HDD to save precious space on my Air. How would I do this? Would I have to install the OS on the HDD or can I simply set the install location right on the HDD? Also, will USB 3.0 be fast enough to play games like Diablo III, etc...?

One more question.

I would also like to install Windows 7 (and eventually 8) onto the HDD. How would I do this?

Thanks

 

[GGJstudios]

Many apps will fail to function or update properly if they're moved from the /Applications folder. You're better off moving user files to the external, rather than apps or system files.

Freeing up space in Mac OS X

 

[jarnold]

Windows Go will solve most of your problems in a few months.